The WEIR SMM 150/15 is a dual‑rail 5 VDC/15 VDC switching power supply used in CNC racks and industrial control panels. Common failure modes include capacitor degradation or rupture on the output side, overheating of the internal MOSFETs or voltage regulator, and loss of output regulation due to damaged switching inductors or diodes. Initial checks should verify that the input voltage is within 110–120 V AC (or 220‑240 V AC) and that the current rating matches the spec; then measure the 5 V and 15 V outputs for correct levels, inspect for bulging or leaking electrolytics, and examine the power‑switching components for burn marks. If output voltages are unstable or missing, replace suspect capacitors and test the switching regulator IC before considering a full board rebuild.[oss-gpt-20b]